For the Two - issue tracker scenario, did you know that JIRA has a built-in Bugzilla Importer? If you want to learn more about consolidating all of the Issues on JIRA, click to: http://www.atlassian.com/software/jira/docs/latest/bugzilla_import.html

Also, if you have other projects that use JIRA and want to migrate their issues into Project Kenai, this is fully doable. Kenai is running JIRA 3.13 that has the new project import feature ( http://tinyurl.com/9p2t8n ) that lets you migrate projects.

If you have any questions, reach me directly daniel at atlassian dot com.